Prepare the filling

• Heat a pan or kadai and when it is hot, add the oil. Add the mustard seeds, urad dal, chana dal, and asafoetida when the oil is hot. Let it splutter and then add the curry leaves, slit green chilies, and ginger and cook for 30 seconds. Then add the chopped onion.
• Cook until the onions are soft, and then add the grated bottle gourd, salt, and turmeric.
• Mix well and cover and cook for 10 to 12 minutes or until the bottle gourd is soft and cooked.
• Make sure to mix in between and do not leave it unattended. Remove the lid and cook for five more minutes or until the water evaporates. Add the cilantro and mix well. The filling is now ready. Remove the green chilies and let it cool.

Prepare the bottlegourd masala dosa.

Method 1

• Heat a well seasoned cast-iron pan, and when it is hot, reduce the heat to medium-low. Take a spoon/ladle full of batter and pour it onto the pan. Spread it evenly but slightly thick. Spread some oil around the edges; ½ tsp should be sufficient. Let the top side cook.
• Reduce the heat to low. Now take two tbsp of the prepared lauki masala filling, add it to one side of the dosa, and spread it on that side. Let it cook for 40 to 50 seconds.
• Gently fold the dosa in half and remove it from the tawa.

Method 2

• Instead of spreading the batter thick, you can make it slightly big and even. Let the top side cook, add the masala in the center, and spread it in the center. Now fold each end of the dosa towards the center like below.
• Similarly, prepare the dosa with the remaining batter.